The Sims 4 Wiki Guide

Child

As a child you to to Grade School. As usual, you start off with a C grade and need to improve it. You'll get daily "Progress Reports" basically saying that you either went up a grade or didnt' change at all.

To improve your grade you need to not only do your homework (and sometimes extra credit) but you need to level up stills to level 4. Another thing is, you need to go to school "Energized" once.

As your grade goes up you have to level up more skills and do more extra credit.

Aging up: To age up, have a sim make a cake and then "Add Candles" to the finished product.

IF you do not age a sim up, it will automatically do so after a couple days. This will lead to a Sad emotion because the sims thinks that their birthday was forgotten.